Improvement in skelping-dies



MILDRED BLAKEY, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN SKELPING-DIES.

Specification forming part of Letters Patent No. 70,397, dated November 5, 1867.

To all whom 'it may concern:

Be it known that IfMILDRED BLAKEY, of the city of Pittsburg, in the county of Alleghen y and State of Pennsylvania, haveinvented a new and useful Improvement in Skelping Dies; and I do hereby declare the following to beafull, clear, and exact description thereof.

Metal pipe other than such as is formed by the exudation of molten metal through properly shaped dies4 or by casting, is usually made by folding long sheets or strips of rolled metal, and welding the edges, where folded, together. This foldin gis usually done by drawing such sheets and strips through between the converging concave faces of a pair of skelpin g'dies, the two dies at the forward end, when closed together, having a front aperture of a nearly tubular shape. Such dies are made in two parts, withthe plane of division running longitudinally and vertically through them, and the two parts are hinged together at the top. To operate them, it is necessary to open up the hinged die, introduce the metallic strip or skelpbar from which the pipe is to be made so far that its forward end shall project somewhat beyond the forward end of the dies, close down the hinged die, to do which requires suficient force to fold the skelp-bar to a tubular shape, and then, after properly fastening the movable hinged die, catch the projecting forward end of the skelp-bar with a pair of tongs and draw the bar through.

My invention relates to the construction of improved dies for the purposes above set forth, and consists in making a slot or opening in such dies along the line of division of the upper parts sufficiently large to admit the jaws of a pair of tongs. I then dispense with the hinging of one of the dies, make both fixed, catch the skelp-bar at the middle of one end with a pair of tongs, introduce it into the dies at the iiaring end, and draw it through, passing the jaws of the tongs along the slot or opening in the upper part of the dies.

To enable others skilled in the art to make and use my invention, l will proceed to .describe its construction and mode of operation,

referring for th at purpose to the drawings herea to annexed, in which- Figure l is a perspective view of my improved skelping=dies, showing their construea tion and how used. Fig. 2 is a front view of the dies and skelp, showing the mode of making lap-weld pipe; and Fig. 3 isfa similar View, showing' the mode of making butt-weld pipe.

Like letters of reference indicate like parts.

A A are two dies, similar in shape and construction, securely fastened to any convenient bed or foundation, B. The dies are concave on their inner faces in the line of their crosssections, of a nearly tubular shape in front, as at c,` and aring toward their rear ends, as at a'.

Along the top of the dies A A, or between them, and longitudinally therewith, I make a slot or opening, b, sufficiently wide to admit of the passage of the jaws c of a pair of tongs.Y

The skelp-bar d, being a fiat sheet of metal of the proper width, is caught at or about the middle of one end by the tongs, introduced into the dies A A at the aring end a', and pulled through, the tongs passing along the slot or opening b,as shown in Fig. l. The

force requisite to this is applied to the handles e e of the tongs in any convenient way, the tongs all the while retaining their gripe on the skelp-bar d.

The edges of the bar d are, by the concave faces of the dies A A, folded down and under, so as to form a skelp, the edges of which, when welded together, give the pipe or tube required. In this way the skelp bars or blanks are passed through one after another as rapidly as may be desired.

The bottom part of the dies is made slightly different for forming butt or lap weld skelps, as may be required.

For a lap-weld the bottom edges of the dies A A are usually ltted neatly together,| and by a finger or guide, properly inserted at any convenient point, one of thevedges of the skelp s l is made to overlap the other slightly, as shown in Fig. 2.

In dies for making a buttweld skelp, a slot or opening is left between the dies on the bottom, and a tongue, t', Fig. 3, placed therein, which projects slightly upward, and against which the sides or edges of the skelp-blank s are bent, as in Fig. 3.

In either case the operation of the machine is substantially thesame as is above described. The skelps, when made, are welded in the usual way.

better skelp, since, with the ordinary mode of doing such work, the skelp bar or blank is apt to be kinked in closing down the hinged die, with consequent loss in the pipe when made.

The dies A A may be made separate Or tO- gether, so as to form a single die, with two If made separate faces Opposite each other.

they may be easily adjusted on the bed B, so as tO form the skelp exactly of the proper size. Having described my improvement, what I claim as my invention, and desire to secure by- Letters Patent, is-

The construction and use of skelping-dies made either solid or separate, with a slot or Opening, b, extending longitudinally along their upper part, through Or between them,

`substantially as and for the purposes hereinbefore set forth.

In testimony whereof I, the said MILDRED BLAKEY, have hereunto set my hand.

MILDRED BLAKEY.

Witnesses:

GEO. H. CHRISTY, A. S. NICHOLSON. 

